Auxiliary beam letoff mechanism for looms



Dec. 29, 1953 Filed Jan. 4, 1952 J. A. BRADSHAW 2,664,114 AUXILIARY BEAMLE'IQFF mcHANI su FOR Locus 3 Sheets-Sm 1 Fi i INVENTOR.

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AUXILIARY BEAM LETOFYF MECHANISM FQR gous Filed Jan. 4, 1952 sSheetQ-Sheet 2 IN VEN TOR.

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Dec. 29, 1953 2,664,114

J. A. BRADSHAW AUXILIARY BEAM LETOFF MECHANIM LOQMS Filed .Jan. 4, 1952s Shani-she p's A INVENTOR.

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Patented Dec. 29, 1953 AUXILIARY BEAM LETOFF MECHANISM FOR LOOMS John A.Bradshaw, Greenville, S. 0., assignor to J. P. Stevens & 00., Inc., acorporation of Dela.-

ware

Application January 4, 1952, Serial No. 264,931

Claims.

This invention relates to letoff mechanisms for looms and moreparticularly to an improved mechanism of this sort for use in looms onwhich an auxiliary warp beam is employed for supplying supplementarywarp ends in addition to the warp ends fed from a main beam to the loom.

In weaving fabrics such as Seersucker cloth and the like, which arecharacterized by a puckered effect in the fabric, it is necessary toprovide slack in certain of the warp ends in order to produce thispuckered fabric texture, This is commonly done by feeding certain of thewarp ends to the loom from a main warp beam in the usual manner and atthe usual tension, and the providing an auxiliary warp beam from whichsupplementary warp yarns are fed separately to the loom at the necessarydegree of slack. Usually the auxiliary warp beam is mounted above themain warp beam, and is therefore referred to as a top beam, and theletoff mechanism of the present invention is uniquel adapted forunwinding the warp ends from a top beam of this sort at a regular ratefor the degree of slack feeding desired or found necessary in anyparticular case.

The letoff mechanism of the present invention is described in detailbelow in connection with the accompanying drawings, in which:

Fig. 1 is a side elevation illustrating the manner in which a letoffmechanism constructed in accordance with the present invention isinstalled on a loom, the loom being represented only fragmentarily.

Fig. 2 is a fragmentar detail view related to Fig. 1 to show the mannerin which the letoff mechanism of the present invention may be connectedfor actuation from a main operating element of the loom;

Fig. 3 is a fragmentary elevation taken from jiggle Jrear of the loom asseen from the left in Fig. 4 is a further detail view related to Fig. 3to show the other end of the letoff mechanism driving drum;

Fig. 5 is a sectional detail taken substantially on the line 5--5 inFig. 3;

Fig. 6 is a further detail taken substantially on the line 66 in Fig. 3;and 1 Fig. 7 is a sectional detail taken substantially on the line '!-'Iin Fig. 1.

Referring now in detail to the drawings, and more particularly at firstto Fig. l, the-letoff mechanism of the present invention is shown ascomprising a frame structure as indicated generally by the rcferencenumeral l0, which is .ar-

ranged for attachment to a conventional loom frame illustratedfragmentarily at F, and which may be provided with bracing arms [2 forfurther support from the loom arch indicated at A.

This frame structure I0 is adapted according to the present inventionfor carrying a driving drum I4, as will be explained more in detailpresently, and is formed with guideways as at I6 for positioning anauxiliary warp beam B so that a warp end package P wound thereon willrest in peripheral driving contact on the driving drum I l. Theguideways l6 are also preferably formed with a lip portion I8 at theirupper ends to provide an elevated rest position for the warp beam B freeof the driving drum I4 to facilitate its handlin upon installation andthreading in the loom. The guideways l6 otherwise extend downwardly inthe frame structure In with a reach suflicient to accommodate the fulldisplacement of the warp beam B while supported peripherally on thedriving drum M as it moves from full position (as shown by full lines inFigs. 1 and 3) to the empty position indicated by dotted lines at B.

It should also be noted that the guideways l5 are not arranged radiallwith respect to the driving drum id, but are offset so as to be alignedmore nearly in a tangent relation with the driving drum [4 at the sidethereof that moves downwardly as the drum [4 rotates in order to obtainan increasing wedging effect between the rotating driving drum l4 andthe opposing face of each guideway [6 as a warp end package P is unwoundfrom the warp beam B, and thereby compensate for the loss in weight ofthe unwinding warp beam B so that an effective driving contact ismaintained with driving drum [4 until the warp beam B is completelyexhausted. In particular cases, it may be desirable to provide veryaccurately for obtaining this increasing wedging effect in relation tothe weight loss of the beam B, and

for this purpose the guideways l6 might be arranged with a calculatedcurvilinear form having the upper portion thereof at a more or lessradial relation to reduce the wedging effect to a minimum at .fullposition of the warp beam B and arrangement for the guideways l6 asillustrated in the drawings will provide satisfactory results.

The driving drum M is formed in a length less than the spacing betweenthe end flanges of the warp beam B, so as to operate in driving contactonly with the warp end package P wound between these end flanges, and isinvested with a surface covering as at formed of cork or other suitablematerial to provide it with a satisfactory surface driving action. Also,particularly where filament yarns are to be handled in the warp endpackage P carried by the warp'beam -.B, there is considerable advantagein relieving this surface covering 20 in a pattern such as is providedby the spiral grooves 20', and by which the effective supporting portionof the surface covering 20 is continuously shifted laterally as thedriving drum I4 is rotated. By this arrangement, the peripheral drivingcontact of the drum I4 with the package P is continuously shifted inrelation to the individual ends of the package P so that an opportunityis afforded for distribution of any inequalities in tension between theindividual ends such as must often be dealt with in handling filamentyarns. The spiral grooves 28' may start at each end of the driving drumI4 as illustrated in the drawings, so as to meet in a V-formati'onmidway thereof, or the spiral may run continuously from one end of thedrum I4 to the other, or any other comparable relieved pattern that willprovide the laterally shifting support by the surface covering 20 asdescribed above may be used as desired. The manner in which the drivingdrum I4 is carried on the frame structure I0 is illustrated best inFigs. 3 and 4, in which the driving drum I4 is shown journalled inhousings 22 and 22 that are supported on tie rods 24 and 26 forming partof the frame structure I0, the tie rod 24 extending entirely across theframe structure I0 while the tie rods 26 extend only from each side tothe adjacent housings 22 or 22.

Actuation 0f the letoff mechanism of the present invention isaccomplished directly from a main operating element of the loom withwhich it is associated, and for this purpose the embodiment shown in thedrawings is equipped with an actuating rod 28 (compare Figs. 1 and 2).fitted at one end with an eccentric collar 30 assembled on an eccentric32 adapted to be fixed on the loom cam shaft C as illustrated in Fig. 2.At its other end, this actuating rod 28 is connected to the purchase arm34 of a bell crank 36 for a pick mechanism 38, the other arm 40 of whichcarries the shifting pawl 42 of the pick mechanism 38. The purchase arm34 is formed with an elongated slot 44 allowing the actuating rod 28 tobe connected at varying distances from the axis of the bell crank sothat the pick mechanism 38 is rendered adjustable to vary the speed ofrotation transmitted to the driving drum I4 as desired. The shiftingpawl arm 40 of the bell crank 36 is also formed with an elongated slot48 to allow the shifting pawl 42 to be positioned therein properly forsmooth operation in relation to the ratchet or pick Wheel 48 of the pickmechanism 38. The ratchet 48 is fixed on a shaft 50 that also carriesthe bell crank 36 at its outer end, and that is journalled on the framestructure III in a bearing bracket 52 formed with an upstanding armportion 54 adjacent the ratchet 48, in which arm portion 54 an elongatedslot 58 is provided for receiving and positioning a, holding pawl 58 forthe pick mechanism 38 (compare Figs. 3 and 7).

The inner end of the ratchet shaft 50 extends beyond the bearing bracket52 to carry a pinion 60 disposed to engage a gear 62 on a countershaft64 (compare Figs. 3 and 5). This countershaft 64 runs to the adjacenthousing 22 in which the driving drum I4 is journalled, as alreadymentioned above, and carries a pinion 66 engaging an intermediate gear68 that is also journalled in this adjacent housing 22 to run in directengagement with a drive gear I0 carried on the adjacent end of themounting shaft I2 for the driving drum I4. Through this gearedarrangement, the driving drum I4 .is rotated directly and regularly fromthe motion of the loom cam shaft C, or other operating element of theloom, for slack feeding of Warp ends from the warp end packageP on thewarp beam B at a desired degree of slack as adjusted by the pickmechanism 42 in relation to the conventional feeding of warp ends from amain beam (not shown) to the loom.

In order to stabilize the geared drive for the winding drum I4 tooperate smoothly as the letoff mechanism of the present invention isactuated through the pick mechanism 42, the previously mentionedcountershaft 64 which runs to the adjacent driving drum support housing22 is fitted at its other end with a brake mechanism as at 1-4. Thisbrake mechanism (as shown best in-Fig. 6) comprises a brake cylinder 16on which are assembled a pair of pivoted clamping arms I8 and both ofwhich are fitted with brake shoes as at 82 and 84. These clamping arms18 and 88 extend from their common pivot joint at 86 to receive apressure rod 88 at their extending ends. The extending end of theclamping arm 80 is formed to receive this pressure rod 88 through aretaining face as at 98 against which a compression spring 92, disposedover the pressure rod 88, is confined by a nut 94 engaging the extendingthreaded end of pressure rod 88. The other clamping arm 18 is formed torovide a contact face as at 96 for a cam-like portion 98 of amanipulating lever I00 that is pivoted on the other extending end of thepressure rod 88 as at I02 for disposition at a retracted position gainstthe adjacent clamping arm I8 to apply the brake mechanism I4, or forpivoting outwardly from the adjacent clamping lever I8 towards ahorizontal position so that its cam-like portion 98 releases the brakemechanism '14 when desired.

The present invention has been described above for purposes ofillustration only and is not intended to be limited by this descriptionor otherwise except as defined in the appended claims.

I claim:

1. An auxiliary beam letoff mechanism for slack feeding of supplementarywarp ends in a 100m, said letoif mechanism comprising an auxiliary framestructure adapted for attachment to a loom frame, a driving drum carriedby said frame structure, guideways formed in said frame structure forpositioning a warp beam to rest a warp yarn package wound thereon inperipheral driving contact on said driving drum, said guideways beingarranged to extend from their remote ends in a path diverging from aradial direction with respect to said driving drum whereby the lateralreaction force from said driving drum against the opposing face of saidguideways increases upon decrease in diameter of said warp yarn packageand thereby compensates for loss in weight of said package on saiddriving drum during unwinding, and means for rotating said driving drumfrom the motion of a main operating element of said loom at a speedproviding a degree of slack feeding of warp ends from said auxiliarybeam as desired in relation to the warp 'ends fed from a main beam tosaid loom.

2. An auxiliary beam letofl mechanism for slack feeding of supplementarywarp ends in a loom, said letoff mechanism comprising an auxiliary framestructure adapted for attachment to a loom frame for positioning anauxiliary warp beam thereon, a driving drum carried by said framestructure and formed in a length less than the spacing between the endflanges on said auxiliary warp beam for supporting said auxiliary warpbeam in peripheral driving contact with a warp yarn package woundthereon, means connecting said driving drum for rotation from the motionof a main operating element of said loom, and an adjustable pickmechanism interposed in said connecting means for varying the speed ofrotation of said driving drum and thereby adjusting the slack feeding ofwarp ends from said auxiliary beam as desired in relation to the warpends fed from a main beam to said loom.

3. An auxiliary beam letoif mechanism for slack feeding of supplementarywarp ends in a loom, said letoff mechanism comprising a peripheraldriving drum, means for mounting said driving drum in relation to themain frame of a loom and for supporting an auxiliary warp beam with awarp end package wound thereon resting on said driving drum, and meansfor rotating said driving drum from the motion of a main operatingelement of said loom at the desired speed of slack feeding of thesupplementary warp ends from said auxiliary Warp beam in relation to thewarp ends fed from a main Warp beam to said loom, said driving drumbeing formed with a peripheral surface that is relieved in a pattern bywhich the effective supporting portion of said surface is continuouslyshifted laterally as said driving drum is rotated.

4. An auxiliary beam letoff mechanism for slack feeding of supplementarywarp yarns in a loom, said letoif mechanism comprising a peripheraldriving drum, means for rotatably mounting said driving drum in relationto the main frame of a loom and for supporting an auxiliary warp beamwith a warp end package wound thereon resting on said driving drum, anadjustable pick mechanism geared to said driving drum, and meansconnecting said pick mechanism to follow continuously the motion of amain operating element of said loom for rotating said driving drumthrough said adjustable pick mechamsm.

5. An auxiliary beam letoff mechanism for slack feeding of supplementarywarp yarns in a loom having a camshaft for actuating the cyclic weavingoperation thereof, said letoif mechanism comprising an auxiliary framestructure adapted for attachment to the frame of said loom forpositioning an auxiliary warp beam thereon, a driving drum carried bysaid frame structure for supporting said auxiliary warp beam inperipheral driving contact with a warp yarn package wound thereon, anadjustable pick mechanism disposed on said frame structure and geared tosaid driving drum, and an actuating rod connecting said adjustable pickmechanism for operation continuously from said camshaft to rotate saiddriving drum at the rate desired for slack feeding of warp ends fromsaid auxiliary beam in relation to the warp ends fed from a main beam tosaid loom.

JOHN A. BRADSHAW.

References Cited in the file of this patent UNITED STATES PATENTS NumberName Date 1,517,930 Wells Dec. 2, 1924 1,698,497 Gunning Jan. 8, 19292,290,628 Alderfer July 21, 1942 2,489,609 Amidon Nov. 29, 1949

